The processes of LPD technology use the following chemical formulae: EQU H.sub.2 SiF.sub.6 +2H.sub.2 O=6HF+SiO.sub.2 EQU H.sub.3 BO.sub.3 +4HF=BF.sub.4 +H.sub.3 +2H.sub.2 O
at 40.degree. C. or lower temperature
A. The advantages of LPD-SiO.sub.2 are as follows:
(1) The equipment used for LPD is simpler and cheaper than that of a vacuum system and also can be used on larger wafers to grow SiO.sub.2. PA1 (2) The growth conditions can be easily controlled. PA1 (3) The growth temperature is lower than that of thermal Oxide or CVD. This advantage can help maintain the complete structure of the chip and the features of the devices. PA1 (4) There is low thermal stress and good gap fill capability. PA1 (5) There is less leakage of current density. PA1 (6) There is high dielectric breakdown strength. PA1 (7) Using the film can simplify the production process, lower the cost, and enhance packing density when applied in the integration of the production process. PA1 (8) the optionally to photoresist. PA1 (1) a "Mask" material to prevent the expansion and distribution of impurities, PA1 (2) insulator between devices, e.g., field oxide or trench isolation, PA1 (3) dielectrics between multi-metal layers, PA1 (4) VIA formation, PA1 (5) as single "Mask" to finish twin retrograde well structure of CMOS, PA1 (6) LDD (Light Doped Drain) oxide spacer width design. PA1 1. The simple pretreatment method of silicon by nitric acid can assist the growth of LPD-SiO.sub.2. PA1 2. It is not necessary to have a previous high-temperature deposited oxide film on the wafer, which makes the fabrication of an IC more flexible. PA1 3. This method can enhance the deposition rate of SiO.sub.2 and shorten the length of time of the IC fabrication process. PA1 4. The less stress produced inside the LPD-SiO.sub.2 film can increase the IC's reliability. PA1 5. The deposited LPD-SiO.sub.2 film has a smaller dielectric constant which can decrease parasitic capacitance to improve the IC speed.
B. The applications of LPD-SiO.sub.2 in the manufacturing process of integrated circuits are: